1. Field of the Invention
This invention relates to apparatus for the continuous pressing and decatizing of cloth, woven and knitted fabrics, and like material.
2. Description of the Prior Art
German Pat. No. DAS 2,456,921 discloses a system for decatizing fabric comprising a rotatably mounted heatable cylinder, an inner back cloth which, prior to passing around the heatable cylinder is led over a steaming section, and an outer runner cloth which presses the back cloth towards the cylinder. The fabric to be treated is passed between the cylinder and the inner back cloth, and the outer runner cloth is constructed as a pressure belt and is under high tensile stress.
This prior art system is advantageous over previously known cylinder presses in that the pressing treatment occurs without stretching giving rise to a considerably improved sewability. The endless back cloth is, for example, made of satin and circulates without slipping with the pressure belt. The back cloth serves two purposes; on the one hand, the very smooth and even surface of the satin back cloth prevents the relatively coarse surface of the pressure belt from being impressed on the surface of the fabric being treated, and on the other hand, the back cloth serves the purpose of expansionless conveying of the fabric through the steaming section and around the cylinder.
However, the insertion of the back cloth between the fabric and the pressure belt raises a number of problems which may only be overcome with difficulty. For example, quite appreciable wear of the back cloth occurs due to the continuous alternation between the steaming action and the intensive pressing action under high specific contact pressure and at temperatures of between 100.degree. C. and 160.degree. C. The additional costs incurred as a consequence of this wear renders the profitability of the whole process doubtful. These additional costs are made up by the replacement cost of the endless back cloth and the costs of changing this endless back cloth, the latter costs being fairly high inasmuch as the guide and tensioning rollers around which the back cloth passes are comparatively heavy rollers and must be disassembled to replace the worn back cloth. Production is obviously stopped during this period, so that further costs are incurred due to loss of production.
Another disadvantage of the back cloth is that the finish on the fabric being treated differs very greatly between a new and a worn back cloth, so that a change in the quality of fabric finish can be observed over the life of a back cloth. Furthermore, the back cloth prevents direct thermal contact between the pressure belt and the fabric and since the back cloth has an insulating action this reduces the fabric temperature which can be achieved.
It is consequently an object of the invention to provide improved apparatus for pressing and decatising fabric. It is a further object of the invention to provide apparatus in which the endless back cloth may be omitted without giving rise to unacceptable stretching of the fabric being treated.